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Home / Equine Research Bank / Vet Sci / Retrospective Evaluation of Cryptorchid Sidedness at Colorad...
Veterinary sciences2025; 12(9); 796; doi: 10.3390/vetsci12090796

Retrospective Evaluation of Cryptorchid Sidedness at Colorado State University Between 1984 and 2014 and Oakridge Equine Hospital Between 2008 and 2023.

Abstract: Cryptorchidism is a common congenital disorder in male horses characterized by the failure of one or both testes to descend into the scrotum. This developmental anomaly has important clinical, surgical, and economic implications, particularly in breeding animals. This retrospective study investigates the prevalence and laterality of cryptorchidism in a large equine population presented to two veterinary referral hospitals-Colorado State University Veterinary Teaching Hospital (CSU VTH, 1984-2014) and Oakridge Equine Hospital (OEH, 2008-2023). Medical records were reviewed to identify affected horses, and data on breed, age, and laterality of retained testes were collected. Anatomical location of retention (inguinal vs. abdominal) was excluded due to inconsistent documentation across the study period. A total of 777 horses met the inclusion criteria, with Quarter Horses comprising the majority of clinical cases. Quarter Horses exhibited a strong predisposition for left-sided testicular retention, whereas Thoroughbreds and Arabians more commonly presented with right-sided retention. These breed-specific trends in laterality suggest possible developmental factors influencing testicular descent. Understanding these patterns can aid in clinical diagnosis, improve surgical planning, and contribute to evidence-based breeding recommendations aimed at reducing the incidence of cryptorchidism in equine populations.
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Publication Date: 2025-08-23 PubMed ID: 41012723PubMed Central: PMC12474194DOI: 10.3390/vetsci12090796Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Research Overview

Cryptorchidism is a condition in male horses where one or both testes fail to descend into the scrotum. This study analyzed data from two equine hospitals over several decades to determine how often this condition occurs and which side of the body it more commonly affects in different horse breeds.

Purpose and Background

  • Cryptorchidism: A common congenital (present from birth) disorder in male horses.
  • Characterized by failure of one or both testes to descend into the scrotum—a necessary developmental step.
  • Has significant clinical, surgical, and economic impacts, especially in breeding horses.
  • Aims to identify the prevalence (how common it is) and laterality (which side is affected—left or right) of cryptorchidism.
  • Data sourced from veterinary records at two specialized equine hospitals over distinct periods: CSU VTH (1984–2014) and OEH (2008–2023).

Methods and Data Collection

  • Retrospective study design — reviewing existing medical records rather than conducting new experiments.
  • Inclusion criteria: horses diagnosed with cryptorchidism at either CSU VTH or OEH within the specified time frames.
  • Collected data points included:
    • Breed of horse
    • Age at presentation
    • Laterality of retained testis (left or right)
  • Excluded data regarding anatomical location of retained testes (inguinal vs. abdominal) due to inconsistent record-keeping across the years.
  • Total sample size: 777 horses meeting all inclusion criteria.

Key Findings

  • Quarter Horses made up the majority of cryptorchid cases in the study sample.
  • Marked breed-specific trends in testicular retention side (laterality):
    • Quarter Horses showed a strong tendency toward left-sided cryptorchidism.
    • Thoroughbreds and Arabians more commonly exhibited right-sided cryptorchidism.
  • These findings suggest that developmental or genetic factors linked to breed might influence which testis fails to descend.

Clinical and Practical Implications

  • Understanding breed-related patterns in cryptorchidism aids veterinarians in diagnosis and surgical planning, as it informs expectations about which side might be affected.
  • Knowledge of laterality trends can streamline pre-surgical imaging and intervention.
  • Data supports evidence-based breeding recommendations to potentially reduce incidence of cryptorchidism by considering breed predispositions.
  • May guide future research into the developmental biology and genetics underpinning this condition.

Limitations and Considerations

  • Retrospective nature limits control over data consistency and completeness.
  • Exclusion of anatomical retention location limits understanding of detailed testicular positioning patterns.
  • Sample biased toward breeds commonly presented at these hospitals, which may not represent all horse populations.

Summary

  • This study provides valuable insights into how cryptorchidism manifests differently between horse breeds, particularly in terms of which side is affected.
  • Quarter Horses tend to have left-sided cryptorchidism, while Thoroughbreds and Arabians more commonly show right-sided retention.
  • The findings have practical utility for veterinarians and breeders by improving clinical management and informing breeding strategies to reduce the prevalence of this congenital condition.

Cite This Article

APA
Fain H, Hendrickson DA, Buesing MT, Griffenhagen G. (2025). Retrospective Evaluation of Cryptorchid Sidedness at Colorado State University Between 1984 and 2014 and Oakridge Equine Hospital Between 2008 and 2023. Vet Sci, 12(9), 796. https://doi.org/10.3390/vetsci12090796

Publication

Veterinary sciences
ISSN: 2306-7381
NlmUniqueID: 101680127
Country: Switzerland
Language: English
Volume: 12
Issue: 9
PII: 796

Researcher Affiliations

Fain, Hannah
  • Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Hendrickson, Dean A
  • Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Buesing, Matthew T
  • Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Griffenhagen, Gregg
  • Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.

Conflict of Interest Statement

The authors declare no conflicts of interest.

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